// #include <Keypad.h>

// long int current_time= 0;
// long int previous_time= 0;
// int threshold= 4000;
// char key_pressed= '\0';
// int score= 0;

// byte random_row= random(1,5);
// byte random_column= random(1,5);

// const int row_num=4;
// const int col_num=4;

// char keys[row_num][col_num] = {
//   {'1' , '2' , '3' , 'A'},
//   {'4' , '5' , '6' , 'B'},
//   {'7' , '8' , '9' , 'C'},
//   {'*' , '0' , '#' , 'D'}
// };
// char random_element= keys[random_row-1][random_column-1];

// String hint1= "row: "+String(random_row);
// String hint2= "column: "+String(random_column);
// byte random_hint= random(1,3);

// byte row_pins[] = {19,18,5,17};
// byte col_pins[] = {16,4,2,15};

// Keypad k = Keypad(makeKeymap(keys), row_pins, col_pins, row_num, col_num);

// void setup() {
//   // put your setup code here, to run once:
//   Serial.begin(115200);
//   // if(random_hint==1){
//   //   Serial.println(hint2);
//   //   Serial.println(hint1);
//   // }else if(random_hint==2){
//   //   Serial.println(hint1);
//   //   Serial.println(hint2);
//   // }
// }

// void loop() {
//   if(random_hint==1){
//     Serial.println(hint2);
//     Serial.println(hint1);
//   }else if(random_hint==2){
//     Serial.println(hint1);
//     Serial.println(hint2);
//   }
//   while(true){
//     char key= k.getKey();
//     if(key){
//       key_pressed=key;
//     }
//     current_time= millis();
//     if(current_time-previous_time == threshold){
//       if(key_pressed == random_element){
//         score++;
//         if(score>6){
//           Serial.print("YOU WON!!");
//           while(1);
//         }
//         Serial.println("CORRECT GUESS! SCORE: "+ String(score));
//         threshold=threshold-500;
//         if(threshold<500){
//           threshold=500;
//         }
//       }
//       else{
//         Serial.println("YOU LOST!");
//         while(1);
//       }
    
//       previous_time=current_time;
//       break;
//     } 
//   }
// }

#include <Keypad.h>

const int row_num = 4;
const int col_num = 4;

long int current_time = 0;
long int prev_time = 0;
int threshold = 4000;       //  threshold of 2000 ms or 2 seconds
char keypressed = '\0';
int score = 0;

char keys[row_num][col_num] = {
  {'1' , '2' , '3' , 'A'},
  {'4' , '5' , '6' , 'B'},
  {'7' , '8' , '9' , 'C'},
  {'*' , '0' , '#' , 'D'}
};

byte row_pins[] = {19,18,5,17};
byte col_pins[] = {16,4,2,15};

//  making keypad object
Keypad k = Keypad(makeKeymap(keys), row_pins, col_pins, row_num, col_num );

void setup(){
  Serial.begin(115200);
}

void loop(){

  //  picking a random element from 2D array
  byte random_row = random(1,5);
  byte random_column = random(1,5);
  char random_element = keys[random_row-1][random_column-1];

  //  Creating hints
  String hint1 = "Row : " + String(random_row);
  String hint2 = "Column : " + String(random_column);
  byte random_hint = random(1,3);  //  possible values : 1 or 2

  //  picking up a hint
  if (random_hint  ==  1)Serial.println(hint1 + "\t" + hint2);
  else Serial.println(hint2 + "\t" + hint1);



  //  GAME LOOP
  while (true){

    //  looking for a key pressed
    char key = k.getKey();

    //  if valid key is pressed, keypressed will get that key, otherwise, \0
    if (key){
      keypressed = key;
    }



    //  starting timer
    current_time = millis();




    //  checking results and breaking this loop in threshold seconds
    if (current_time - prev_time  ==  threshold){

      //  checking results
      if (keypressed  ==  random_element){
        score++;
        if (score > 6){
          Serial.println("You WON!");
          while(1);
        }
        Serial.println("Correct guess, score : " + String(score));
        threshold = threshold - 500;
        if (threshold < 500)threshold = 500;
      }

      else{
        Serial.println("You LOSE!");
        while(1);
      }

      //  updating prev_time
      prev_time = current_time;
      break;
    }
  }
}